According to the data provided by the Veterinary Hospital of the Saratov State Agrarian University, in the cities of Saratov, Balakovo and Engels, renal and heart failure in patients with endometritis and cats with pyometra were registered in 26.8-34.5% of all surveyed domestic animals. The results of abdominal echography, made by sick cats with pyometra and dogs with endometritis, showed the presence of renal failure of the following types: – 92.9% – glomerulonephritis, pyelonephritis; – 2.4% – focal diseases (cysts); in 4.7% – hydronephrosis. In this group of animals with pathologies were identified: – pyelonephritis, glomerulonephritis in 81.3%; – pathologies of a focal nature (cysts, masses) – in 4.0%; – pathologies of a hereditary nature – in 3.1%; – pathology of the collecting system, incl. hydronephrosis, nephrolithiasis in 10.7% and 0.9% of sick dogs and cats, respectively. Echographically, the signs of heart failure (pericarditis, endcardiosis) are fairly objectively detected in 60.6% of the examined patients with endometritis and in 73.5% of patients with pyometra. Moreover, the combination of renal and heart failure in sick dogs and cats is recorded in 56.79% of cases. In inflammatory diseases in dogs in this case with endometritis and cats with pyometra in acute form, ultrasound shows: an increase in size (especially dorsoventral); the contours of the kidneys are indistinct; cortico-medullary differentiation is weak; the thickness of the parenchyma is heterogeneous and uneven, the collecting system of the kidneys is expanded. Echographically, the signs of heart disease and heart failure are quite objectively detected (pericarditis – 23.97%, endcardiosis – 16.83%, arrhythmias of various origins – 44.2% and other diseases of the heart and vascular system – 14.0%), in 60, 6% of the examined sick dogs with endometritis and 73.5% of sick cats with pyometra. Moreover, the combination in sick dogs and cats of renal and heart failure is recorded in 56.79% of cases.